This invention relates to novel microfilm and to a method of preparation which has improved contrast and which is more easily made than microfilm heretofore.
In the preparation of microfilm, it has become the practice to employ a photopolymer with groups that can be dyed and these groups treated in various ways to render them visible. Thus, the preparation and development of the microfilm was often difficult, time consuming and expensive. In accordance with the invention, however, microfilm structures are provided which do not require special dye forming photopolymer groups and further which can be easily treated to form images of high density and excellent contrast.